Energy and exergy assessment of heavy-duty mining trucks. Discussion of saving opportunities.

Heavy-duty mining trucks are essential for open-pit mining and are significant energy consumers, stressing the need for the mining industry to improve the fuel economy of mining trucks. However, there is a limited discussion on this topic in the specialized literature, mainly focusing on light-duty vehicles. This article discusses the energy and exergy balances of heavy-duty mining trucks operating in an open pit mine in Colombia. Results show saving opportunities by either using batteries or producing hydrogen with the power from regenerative brakes, reducing heat losses in the engine, recovering heat losses with combustion gases using thermoelectric generators, and replacing mechanical pumps with electrical pumps. The assessment shows that reducing engine heat losses by coating the cylinder, cylinder head, and piston crown can reduce fuel consumption between 1.8 % and 9.1 %. Moreover, the production of hydrogen, while economically feasible, needs to assess the implementation of electrolyzers in mining trucks. Other measures are not economically viable. Using batteries, which requires adding 12 t of weight to the truck, reduces truck productivity. Finally, using thermoelectric generators and replacing mechanical pumps shows marginal opportunities to reduce fuel consumption.